When to use parentheses and when not to use in the TestScript?

The customserver has some functions namely the Recordable function and helper function. Summarizing both and looking from the TestScript view, there are functions with return type and functions without return type. The function with return type can be compared to Function Procedure and function without return type can be compared to Sub Procedure, they are described generically as functions in the custom server.

All recordable functions are Sub Procedure as they do not have a return type, while most of the helper functions are Function Procedure. Call to Sub procedure does not require parentheses but call to Function Procedure require parentheses.